CBSE Class 10 Science 2022 · Paper 31/2/2 · Question 11

(i) All the F1 plants have green stems (genotype $\text{Gg}$), because green is the dominant trait. (ii) $\text{green}:\text{purple}=3:1$ in the F2 (genotypes $\text{GG}:\text{Gg}:\text{gg}=1:2:1$). (iii) Green stem colour ($\text{G}$) is dominant and purple ($\text{g}$) is recessive. The purple trait, hidden in every F1 plant, reappears in the F2, so the factor for it was inherited unchanged rather than lost or blended: each plant carries two copies of the factor for stem colour, the two copies separate so that each gamete receives only one, and they come together again at fertilisation.